#include <stdio.h>
#include <stdlib.h>
#include <uv.h>

void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
    *buf = uv_buf_init((char *) malloc(suggested_size), suggested_size);
}

void on_read(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf) {
    if (nread > 0) {
        uv_write_t *req = (uv_write_t *) malloc(sizeof(uv_write_t));

        // Construct the complete HTTP response with appropriate content length
        char response[] = "HTTP/1.1 200 OK\nContent-Type: text/plain\nContent-Length: 13\n\nHello, World!\n";
        uv_buf_t wrbuf = uv_buf_init(response, sizeof(response) - 1);

        uv_write(req, client, &wrbuf, 1, NULL);
        free(buf->base);  // Free the buffer allocated by uv_read_start

        // Close the client connection after writing the response
        uv_close((uv_handle_t *) client, NULL);
    } else if (nread < 0) {
        if (nread != UV_EOF)
            fprintf(stderr, "Read error: %s\n", uv_strerror(nread));
        uv_close((uv_handle_t *) client, NULL);
    }
}


void on_connection(uv_stream_t *server, int status) {
    if (status < 0) {
        fprintf(stderr, "Error on connection: %s\n", uv_strerror(status));
        return;
    }

    uv_tcp_t *client = (uv_tcp_t *) malloc(sizeof(uv_tcp_t));
    uv_tcp_init(uv_default_loop(), client);

    if (uv_accept(server, (uv_stream_t *) client) == 0) {
        uv_read_start((uv_stream_t *) client,
                      alloc_buffer,  // Function to allocate buffer
                      on_read);     // Function to call when data is read
    } else {
        uv_close((uv_handle_t *) client, NULL);
    }
}


int main() {
    uv_loop_t *loop = uv_default_loop();

    uv_tcp_t server;
    uv_tcp_init(loop, &server);

    struct sockaddr_in addr;
    uv_ip4_addr("0.0.0.0", 8000, &addr);

    uv_tcp_bind(&server, (const struct sockaddr *) &addr, 0);
    int r = uv_listen((uv_stream_t * ) & server, 128, on_connection);
    if (r) {
        fprintf(stderr, "Listen error: %s\n", uv_strerror(r));
        return 1;
    }

    printf("Server running at http://127.0.0.1:8000/\n");

    return uv_run(loop, UV_RUN_DEFAULT);
}
